Unit Six: Energy Resources and Consumption Test Review

Renewable and Nonrenewable Resources

  • The primary difference lies in the accessibility and replenishment rate of these resources.
  • Non-renewable resources exist in a finite amount and are consumed upon use.
    • Burning coal in a power plant is an example; once burned, the coal is gone.
    • Fossil fuels (oil, natural gas, and coal) took millions of years to form, making replacement within a human lifetime impossible.
  • Renewable resources are easily replenished.
    • Examples include solar energy, wind energy, geothermal energy, hydropower, tidal energy, and biomass.
    • The Sun powers wind patterns, ensuring wind energy as a renewable resource.
    • Geothermal energy utilizes the Earth's constant heat.
    • Hydropower relies on river flow, which is generally consistent.
    • Tidal energy harnesses ocean tides.
    • Biomass (wood, plant matter) is renewable only if used sustainably, allowing for regrowth.
      • If biomass is consumed faster than it can be replaced, it becomes non-renewable.

Global Distribution of Resources

  • Renewable and non-renewable resources are not evenly distributed worldwide.
  • Accessibility depends on geographical location.
    • Hydropower is prevalent in Brazil due to numerous rivers.
    • Nuclear energy is popular in France.
    • Solar power is effective in the Southeast United States but less so in the cloudy Pacific Northwest.
  • Fossil Fuel Locations:
    • Coal: Russia, U.S., and China.
    • Oil: Iran, Saudi Arabia, Venezuela, and Canada.
    • Natural Gas: U.S., Russia, and Iran.
  • Reserves are the available amount of fossil fuel that we are able to extract.

Energy Trends

  • Industrialized countries shift from biomass subsistence to fossil fuels and advanced resources like nuclear power.
  • During the Industrial Revolution (around 1883), coal usage increased while wood usage declined in the U.S.
  • Petroleum remains a commonly used fuel worldwide.
  • Natural gas use increased after the 1950s.
  • Nuclear power increased after World War II.
  • Hydropower remains relatively stable.
  • Wood usage stays low post-industrialization as electricity becomes the primary energy source.
  • Price, availability, and government regulations influence fuel usage.
    • Increased gas prices may drive consumers to buy more fuel-efficient cars, dropping the use of oil or petroleum.
    • Unrest in the Middle East can cause fuel prices to rise, like the 1970s oil crisis.

Fuel Source Details

  • Biomass:
    • Used as a subsistence form of energy for cooking and heating, especially in less industrialized countries.
    • Includes wood, peat, and charcoal.
      • Charcoal is a wood-based product, not the same as mined coal.
    • Accessible and cheap for less developed countries.
    • Pollution issues include particulate matter affecting lung health and carbon compounds released when burned.
    • Renewable does not necessarily mean clean or pollution-free.
  • Coal:
    • Acquired through mining with environmental impacts: land disturbance, deforestation, erosion, and pollution from mining processes.
    • Types of coal:
      • Lignite: lower heat content, lower sulfur content (less polluting).
      • Bituminous: most commonly used due to large supply and excellent heat content but high in sulfur (very polluting).
        • Sulfur released can mix with water vapor, causing acid deposition (acid rain).
      • Anthracite: high heat content, low sulfur (low polluting), but available in limited quantities.
    • All types release particulate matter (affecting lung health) and carbon pollution (contributing to climate change).
  • Crude Oil:
    • Drilled and pumped from the ground, then converted into other fuels for vehicles and machinery.
    • Energy conversions are inefficient due to the second law of thermodynamics.
      • Much of the energy is released as heat during combustion.
      • Fossil fuel use is overall inefficient.
    • Releases carbon compounds (leading to global warming) and particulate matter (a lung irritant) when burned.
  • Combustion
    • This is when we take a fossil fuel and have it undergo a chemical reaction by reacting it with oxygen to be able to release the energy that we need.
    • When they're not combusted fully or completely, we get basically an incomplete combustion pollution that is going to release, including carbon dioxide, water vapor—which in this case would be harmless—but other particulates as well.
    • One of the ways we can try to at least increase our efficiency is by using something like cogeneration. This is where, let's say, you're burning coal at a power plant to produce electricity. You are going to have excess heat from that process. Generally, that heat is used to boil water to create the electricity because the steam then spins a turbine and so on. But the excess heat that's produced could be used for another purpose, so maybe heating the buildings nearby.
  • Natural Gas:
    • Extracted through fracking (hydraulic fracturing): injecting water, sand, and chemicals at high pressure into shale rock to create cracks and release gas.
    • Problems with fracking: potential earthquakes and groundwater contamination.
    • One of the cleanest fossil fuels with less particulate matter when burned.
    • Releases methane, a potent greenhouse gas.

Power Plants

  • Coal-Fired Power Plants:
    • Coal is burned in a furnace to produce heat.
    • Heat vaporizes water into steam.
    • Steam spins a turbine.
    • The turbine's mechanical energy powers a generator to produce electricity.
  • Nuclear Power Plants:
    • Uses uranium-235, a radioactive isotope of uranium, to create a chain reaction (fission).
    • A neutron hits a uranium atom, causing it to rupture and release more neutrons, generating heat.
    • Heat powers turbines and generators.
    • Radiation released during fission is harmful to human tissues and DNA.
    • Containment is essential to keep radiation inside the reactor.
    • High-level radioactive waste must be disposed of, often stored on-site in dry storage casks.
  • Nuclear Power Plant Function:
    • Similar to coal-fired plants from the steam part onward.
    • Containment structure houses the nuclear reactor, fuel rods, and control rods.
    • Heat from the reactor generates steam.
    • Steam spins a turbine.
    • Turbine powers a generator to produce electricity.
    • Thermal pollution is a concern: hot water released back into reservoirs can harm aquatic life.
  • Nuclear Disasters:
    • Three Mile Island (Pennsylvania, 1970s): partial reactor meltdown, possibly causing cancer increases.
    • Chernobyl (Ukraine, 1986): human error meltdown, area still radioactive.
    • Fukushima (Japan, 2011): earthquake and tsunami damaged the plant, causing reactor meltdowns.

Renewable Energy Sources

  • Solar Energy:
    • Photovoltaic cells capture the sun's energy and transform it into electric energy.
    • Energy can be stored for later use.
    • Concerns: solar farms can block sunlight from reaching the ground, affecting ecosystems.
    • Passive solar energy uses building practices and materials to absorb and retain heat (thermal mass) from the sun during winter.
      • Heat is not storable.
  • Hydroelectric Power:
    • Dams are the most common type.
    • Wave hydroelectric power also exists.
    • Dams have turbines that spin as water passes over it.
    • Turbine spins a generator to produce electricity.
    • Downsides: affect fish migration (fish ladders are used to help fish pass dams), alter river flow.
    • Benefits: reduce flooding, reservoirs can be used for irrigation, drinking water, and recreation.
  • Geothermal Power:
    • Uses heat from the Earth's center to heat water and produce steam.
    • Best in geologically active areas (e.g., plate boundaries like Iceland).
    • Downsides: expensive plants, potential pollution in the form of hydrogen sulfide.
  • Hydrogen Fuel Cells and Wind Energy:
    • Hydrogen fuel cells use hydrogen and oxygen to react and create energy, with water as the only byproduct.
    • Expensive to produce, and hydrogen is explosive.
    • Wind power uses turbines to generate electricity.
    • Downsides: large, noisy, and can kill birds and bats.
      • Best placed in open areas like farmland, away from populated areas and bird/bat migration paths.